What we do
Our main tool, the Pregnancy Calculator, estimates your due date, pregnancy week, month, trimester and timeline from one date. Our second main tool, the Due Date Calculator, focuses on the estimated due date using the last period, conception, IVF or ultrasound dating.
Around them we have built tools for every stage of the journey, each one for a real question parents ask:
- Trying to conceive: Ovulation Calculator, Period Calculator, Implantation Calculator and Pregnancy Test Calculator.
- During pregnancy: week, month, trimester and timeline calculators, the Pregnancy Weight Gain Calculator, the Pregnancy Calorie Calculator, the Twin Due Date Calculator, the hCG Calculator, a Contraction Timer and a Kick Counter, plus week-by-week and month-by-month guides.
- After birth: the Baby Growth Percentile Calculator (WHO charts), Baby Formula Calculator, Baby Sleep Calculator, Baby Age Calculator and the Corrected Age Calculator for babies born early.
- Everyday dates: a general Date Calculator.
Every tool is free, works on any phone, and needs no sign-up.
How we keep calculations accurate
All calculations count whole calendar days, so month lengths and leap years are always handled correctly. We use the standard conventions found in prenatal care — 280 days from the last period, 266 days from conception, embryo-age-adjusted IVF dating — and show the method under every result so you can check it. The calculators are covered by automated tests for edge cases such as February 29, month ends, future dates and invalid input.
How we write our content
Our guides describe what commonly happens in pregnancy in general terms. Timings of tests and appointments vary between countries and care providers, so we describe typical schedules rather than instructions. We never present an estimate as a medical certainty. The guidelines and conventions behind each calculator are listed on our Sources & Methods page.
Privacy
The calculators run in your browser and the dates you enter are not stored. See our Privacy Policy.
Medical information
Pregnancy Calculator provides estimates for informational purposes only. Please read our Medical Disclaimer.